/*
 * Copyright (C) The Apache Software Foundation. All rights reserved.
 *
 * This software is published under the terms of the Apache Software
 * License version 1.1, a copy of which has been included with this
 * distribution in the LICENSE.APL file.  */

package org.apache.log4j.helpers;

/**
   SingleLineTracerPrintWriter overrides the println function in
   TracerPrintWriter by replacing the TAB character with spaces.
   It also does not print the "\n".
   

   The default format generated by TracerPrintWriter for exceptions
   prints on multiple lines, which does not interact well with some
   logging systems. On the other hand, a stack-trace on one line can be a
   mite difficult to read, so this class should only be used where really
   necessary :-)
   

   For syslog daemons, tabs in messages are not friendly, hence the
   replacement of tabs by spaces here. It shouldn't do any harm to
   do this for all messages...
   

   Perhaps it might be better to enhance TracerPrintWriter to have
   a configuration item for one-line or multi-line mode...
*/
public class SingleLineTracerPrintWriter extends TracerPrintWriter {

  static String TAB = "    ";

  public SingleLineTracerPrintWriter(QuietWriter qWriter) {
    super(qWriter);
  }

  /**
     Make the first Exception line print properly by omitting the \n at the
     end.
  */
  public
   void println(Object o) {
    this.qWriter.write(o.toString());
  }

  // Note: the Char[] form is handled by the TracerPrinterWriter super
  // class

  /**
     Remove the first character from the string (usually a TAB) and do
     not print "\n"
  */   
  public
  void println(String s) {
      // remove '^I' and replace it with 4 spaces
      this.qWriter.write(TAB+s.substring(1));
  }
}